[PATCH] Generic compat_sys_fallocate

[PATCH] Generic compat_sys_fallocate

[Kyle McMartin]

Basically everyone is using the same sys32_fallocate. Delete a whole bunch of
archdep code and move the compat wrapper to fs/compat.c

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
---

NOTE: Patch hunk in scall64-o32.S depends on a patch going in through
Ralf's linux-mips tree.

---
 arch/mips/kernel/linux32.c        |    7 -------
 arch/mips/kernel/scall64-o32.S    |    2 +-
 arch/powerpc/kernel/sys_ppc32.c   |    7 -------
 arch/sparc64/kernel/sys_sparc32.c |    6 ------
 arch/x86_64/ia32/ia32entry.S      |    2 +-
 arch/x86_64/ia32/sys_ia32.c       |    7 -------
 fs/compat.c                       |   10 ++++++++++
 include/linux/compat.h            |    2 ++
 8 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 135d9a5..c37568d 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -566,13 +566,6 @@ asmlinkage long sys32_fadvise64_64(int fd, int __pad,
 			flags);
 }
 
-asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_a2,
-	unsigned offset_a3, unsigned len_a4, unsigned len_a5)
-{
-	return sys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
-	                     merge_64(len_a4, len_a5));
-}
-
 save_static_function(sys32_clone);
 static int noinline __used
 _sys32_clone(nabi_no_regargs struct pt_regs regs)
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index dd68afc..bb724cc 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -525,5 +525,5 @@ sys_call_table:
 	PTR	compat_sys_signalfd
 	PTR	compat_sys_timerfd
 	PTR	sys_eventfd
-	PTR	sys32_fallocate			/* 4320 */
+	PTR	compat_sys_fallocate		/* 4320 */
 	.size	sys_call_table,.-sys_call_table
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index bd85b5f..b42cbf1 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -773,13 +773,6 @@ asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
 	return sys_truncate(path, (high << 32) | low);
 }
 
-asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
-				     u32 lenhi, u32 lenlo)
-{
-	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
-			     ((loff_t)lenhi << 32) | lenlo);
-}
-
 asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
 				 unsigned long low)
 {
diff --git a/arch/sparc64/kernel/sys_sparc32.c b/arch/sparc64/kernel/sys_sparc32.c
index e8dce90..5d60883 100644
--- a/arch/sparc64/kernel/sys_sparc32.c
+++ b/arch/sparc64/kernel/sys_sparc32.c
@@ -1028,9 +1028,3 @@ long compat_sync_file_range(int fd, unsigned long off_high, unsigned long off_lo
 				   flags);
 }
 
-asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
-				     u32 lenhi, u32 lenlo)
-{
-	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
-			     ((loff_t)lenhi << 32) | lenlo);
-}
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 18b2318..28d8fff 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -732,5 +732,5 @@ ia32_sys_call_table:
 	.quad compat_sys_signalfd
 	.quad compat_sys_timerfd
 	.quad sys_eventfd
-	.quad sys32_fallocate
+	.quad compat_sys_fallocate
 ia32_syscall_end:
diff --git a/arch/x86_64/ia32/sys_ia32.c b/arch/x86_64/ia32/sys_ia32.c
index bee96d6..ca8deac 100644
--- a/arch/x86_64/ia32/sys_ia32.c
+++ b/arch/x86_64/ia32/sys_ia32.c
@@ -880,10 +880,3 @@ asmlinkage long sys32_fadvise64(int fd, unsigned offset_lo, unsigned offset_hi,
 				len, advice);
 }
 
-asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_lo,
-				unsigned offset_hi, unsigned len_lo,
-				unsigned len_hi)
-{
-	return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
-			     ((u64)len_hi << 32) | len_lo);
-}
diff --git a/fs/compat.c b/fs/compat.c
index 15078ce..2629a25 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -2226,3 +2226,13 @@ asmlinkage long compat_sys_timerfd(int ufd, int clockid, int flags,
 }
 
 #endif /* CONFIG_TIMERFD */
+
+asmlinkage long compat_sys_fallocate(int fd, int mode,
+				     u32 offset_lo, u32 offset_hi,
+				     u32 len_lo, u32 len_hi)
+{
+	u64 offset = ((u64)offset_hi << 32) | offset_lo;
+	u64 len = ((u64)len_hi << 32) | len_hi;
+
+	return sys_fallocate(fd, mode, offset, len);
+}
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 0e69d2c..a770c6c 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -266,6 +266,8 @@ asmlinkage long compat_sys_signalfd(int ufd,
                                 compat_size_t sigsetsize);
 asmlinkage long compat_sys_timerfd(int ufd, int clockid, int flags,
 				const struct compat_itimerspec __user *utmr);
+asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset_lo,
+				u32 offset_hi, u32 len_lo, u32 len_hi);
 
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */
-- 
1.5.3.2

Re: [PATCH] Generic compat_sys_fallocate

[Kyle McMartin]

On Fri, Sep 28, 2007 at 09:01:37PM +0200, Arnd Bergmann wrote:
> 
> This code assumes little-endian register ordering for 64 bit
> arguments. AFAICS, this is wrong at aleast on mipseb and powerpc.
> 

Yeah, you're right. I've an idea for how to fix this, will update patch
soon.

Cheers,
	Kyle

Re: [PATCH] Generic compat_sys_fallocate

[Heiko Carstens]

On Fri, Sep 28, 2007 at 02:11:11PM -0400, Kyle McMartin wrote:
> Basically everyone is using the same sys32_fallocate. Delete a whole bunch of
> archdep code and move the compat wrapper to fs/compat.c
> 
> Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
> --- a/arch/sparc64/kernel/sys_sparc32.c
> +++ b/arch/sparc64/kernel/sys_sparc32.c
> @@ -1028,9 +1028,3 @@ long compat_sync_file_range(int fd, unsigned long off_high, unsigned long off_lo
>  				   flags);
>  }
> 
> -asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
> -				     u32 lenhi, u32 lenlo)
> -{
> -	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
> -			     ((loff_t)lenhi << 32) | lenlo);
> -}
> diff --git a/arch/x86_64/ia32/sys_ia32.c b/arch/x86_64/ia32/sys_ia32.c
> index bee96d6..ca8deac 100644
> --- a/arch/x86_64/ia32/sys_ia32.c
> +++ b/arch/x86_64/ia32/sys_ia32.c
> @@ -880,10 +880,3 @@ asmlinkage long sys32_fadvise64(int fd, unsigned offset_lo, unsigned offset_hi,
>  				len, advice);
>  }
> 
> -asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_lo,
> -				unsigned offset_hi, unsigned len_lo,
> -				unsigned len_hi)
> -{
> -	return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
> -			     ((u64)len_hi << 32) | len_lo);
> -}

These are not identical... the least and most significant parts seem to get
passed in a different way on little and big endian machines.
Maybe it would be worth to have something like compat_merge_64() which does
the right thing?

Re: [PATCH] Generic compat_sys_fallocate

[Kyle McMartin]

On Sat, Sep 29, 2007 at 07:06:10AM +0200, Heiko Carstens wrote:
> 
> These are not identical... the least and most significant parts seem to get
> passed in a different way on little and big endian machines.
> Maybe it would be worth to have something like compat_merge_64() which does
> the right thing?
> 

yeah, that's what i've just done.

cheers,
	Kyle

[COMPAT] Add compat_merge64 helper

[Kyle McMartin]

To be used when endianness matters for argument ordering when reassembling
a 64-bit value out of two register halves.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
---
 include/linux/compat.h |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 0e69d2c..07bcc3c 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -267,5 +267,14 @@ asmlinkage long compat_sys_signalfd(int ufd,
 asmlinkage long compat_sys_timerfd(int ufd, int clockid, int flags,
 				const struct compat_itimerspec __user *utmr);
 
+static inline u64 compat_merge64(u32 left, u32 right)
+{
+#if defined(__BIG_ENDIAN)
+	return ((u64)left << 32) | right;
+#else /* defined (__LITTLE_ENDIAN) */
+	return ((u64)right << 32) | left;
+#endif
+}
+	
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */
-- 
1.5.3.2

[PATCH] Generic compat_sys_fallocate

[Kyle McMartin]

Basically everyone is using the same sys32_fallocate. Delete a whole bunch of
archdep code and move the compat wrapper to fs/compat.c

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
---
 arch/mips/kernel/linux32.c        |    7 -------
 arch/mips/kernel/scall64-o32.S    |    2 +-
 arch/powerpc/kernel/sys_ppc32.c   |    7 -------
 arch/sparc64/kernel/sys_sparc32.c |    6 ------
 arch/x86_64/ia32/ia32entry.S      |    2 +-
 arch/x86_64/ia32/sys_ia32.c       |    7 -------
 fs/compat.c                       |   10 ++++++++++
 include/linux/compat.h            |    2 ++
 8 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 135d9a5..c37568d 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -566,13 +566,6 @@ asmlinkage long sys32_fadvise64_64(int fd, int __pad,
 			flags);
 }
 
-asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_a2,
-	unsigned offset_a3, unsigned len_a4, unsigned len_a5)
-{
-	return sys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
-	                     merge_64(len_a4, len_a5));
-}
-
 save_static_function(sys32_clone);
 static int noinline __used
 _sys32_clone(nabi_no_regargs struct pt_regs regs)
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index b3ed731..bb724cc 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -525,5 +525,5 @@ sys_call_table:
 	PTR	compat_sys_signalfd
 	PTR	compat_sys_timerfd
 	PTR	sys_eventfd
-	PTR	sys_fallocate			/* 4320 */
+	PTR	compat_sys_fallocate		/* 4320 */
 	.size	sys_call_table,.-sys_call_table
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index bd85b5f..b42cbf1 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -773,13 +773,6 @@ asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
 	return sys_truncate(path, (high << 32) | low);
 }
 
-asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
-				     u32 lenhi, u32 lenlo)
-{
-	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
-			     ((loff_t)lenhi << 32) | lenlo);
-}
-
 asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
 				 unsigned long low)
 {
diff --git a/arch/sparc64/kernel/sys_sparc32.c b/arch/sparc64/kernel/sys_sparc32.c
index e8dce90..5d60883 100644
--- a/arch/sparc64/kernel/sys_sparc32.c
+++ b/arch/sparc64/kernel/sys_sparc32.c
@@ -1028,9 +1028,3 @@ long compat_sync_file_range(int fd, unsigned long off_high, unsigned long off_lo
 				   flags);
 }
 
-asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
-				     u32 lenhi, u32 lenlo)
-{
-	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
-			     ((loff_t)lenhi << 32) | lenlo);
-}
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 18b2318..28d8fff 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -732,5 +732,5 @@ ia32_sys_call_table:
 	.quad compat_sys_signalfd
 	.quad compat_sys_timerfd
 	.quad sys_eventfd
-	.quad sys32_fallocate
+	.quad compat_sys_fallocate
 ia32_syscall_end:
diff --git a/arch/x86_64/ia32/sys_ia32.c b/arch/x86_64/ia32/sys_ia32.c
index bee96d6..ca8deac 100644
--- a/arch/x86_64/ia32/sys_ia32.c
+++ b/arch/x86_64/ia32/sys_ia32.c
@@ -880,10 +880,3 @@ asmlinkage long sys32_fadvise64(int fd, unsigned offset_lo, unsigned offset_hi,
 				len, advice);
 }
 
-asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_lo,
-				unsigned offset_hi, unsigned len_lo,
-				unsigned len_hi)
-{
-	return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
-			     ((u64)len_hi << 32) | len_lo);
-}
diff --git a/fs/compat.c b/fs/compat.c
index 15078ce..9093915 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -2226,3 +2226,13 @@ asmlinkage long compat_sys_timerfd(int ufd, int clockid, int flags,
 }
 
 #endif /* CONFIG_TIMERFD */
+
+asmlinkage long compat_sys_fallocate(int fd, int mode,
+				     u32 offset_lo, u32 offset_hi,
+				     u32 len_lo, u32 len_hi)
+{
+	u64 offset = compat_merge64(offset_lo, offset_hi);
+	u64 len = compat_merge64(len_lo, len_hi);
+
+	return sys_fallocate(fd, mode, offset, len);
+}
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 07bcc3c..49401a9 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -266,6 +266,8 @@ asmlinkage long compat_sys_signalfd(int ufd,
                                 compat_size_t sigsetsize);
 asmlinkage long compat_sys_timerfd(int ufd, int clockid, int flags,
 				const struct compat_itimerspec __user *utmr);
+asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset_lo,
+				u32 offset_hi, u32 len_lo, u32 len_hi);
 
 static inline u64 compat_merge64(u32 left, u32 right)
 {
-- 
1.5.3.2

Re: [PATCH] Generic compat_sys_fallocate

[Geert Uytterhoeven]

On Fri, 28 Sep 2007, Kyle McMartin wrote:
> --- a/fs/compat.c
> +++ b/fs/compat.c
> @@ -2226,3 +2226,13 @@ asmlinkage long compat_sys_timerfd(int ufd, int clockid, int flags,
>  }
>  
>  #endif /* CONFIG_TIMERFD */
> +
> +asmlinkage long compat_sys_fallocate(int fd, int mode,
> +				     u32 offset_lo, u32 offset_hi,
> +				     u32 len_lo, u32 len_hi)
> +{
> +	u64 offset = compat_merge64(offset_lo, offset_hi);
> +	u64 len = compat_merge64(len_lo, len_hi);
> +
> +	return sys_fallocate(fd, mode, offset, len);
> +}

To avoid confusion, you may want to rename the *_{lo,hi} parameters to
e.g. *_{l,r}, as they don't actually mean the low and high part anymore.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds